Despite recent improvements in renal allograft survival, the loss of graft function due to acute and chronic rejection continues and is a leading cause of end-stage renal failure today. As the occurrence of acute rejection episodes is the most powerful predictive factor for the later development of chronic rejection in adults and children, many advocate strategies to detect and ablate acute rejection episodes as early as possible.
Procedures to diagnose renal allograft rejection depend upon detection of graft dysfunction and the presence of a mononuclear leukocytic infiltrate. However, the presence of a modest cellular infiltrate is often not conclusive and can be detected in non-rejecting grafts. It would be helpful to have a reliable tool for diagnosis and follow-up of acute renal allograft rejection.